You know what grinds my gears most of all? Musical instruments. Guitars, harmonicas, etc. There is nothing worse than some hipster d-bag who pulls out his guitar and starts playing around a campfire. Video gear or a cellphone are most likely only taking a few minutes, and it's easier to ask someone to step away from the shelter when using their phone. Try doing the same thing to a musician at a shelter. A harmonica and guitar duet at 7pm can go for hours.